SequenceBarrier (Disruptor)

```
public interface SequenceBarrier
```
Coordination barrier for tracking the cursor for publishers and sequence of dependent EventProcessors for processing a data structure

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`alert()`	Alert the `EventProcessor`s of a status change and stay in this status until cleared.
`void`	`checkAlert()`	Check if an alert has been raised and throw an `AlertException` if it has.
`void`	`clearAlert()`	Clear the current alert status.
`long`	`getCursor()`	Get the current cursor value that can be read.
`boolean`	`isAlerted()`	The current alert status for the barrier.
`long`	`waitFor(long sequence)`	Wait for the given sequence to be available for consumption.

- Method Detail
  - waitFor
```
long waitFor(long sequence)
      throws AlertException,
             java.lang.InterruptedException,
             TimeoutException
```
    Wait for the given sequence to be available for consumption.
    
    Parameters:
    
    sequence - to wait for
    
    Returns:
    
    the sequence up to which is available
    
    Throws:
    
    AlertException - if a status change has occurred for the Disruptor
    
    java.lang.InterruptedException - if the thread needs awaking on a condition variable.
    
    TimeoutException - if a timeout occurs while waiting for the supplied sequence.
  - getCursor
```
long getCursor()
```
    Get the current cursor value that can be read.
    
    Returns:
    
    value of the cursor for entries that have been published.
  - isAlerted
```
boolean isAlerted()
```
    The current alert status for the barrier.
    
    Returns:
    
    true if in alert otherwise false.
  - alert
```
void alert()
```
    Alert the EventProcessors of a status change and stay in this status until cleared.
  - clearAlert
```
void clearAlert()
```
    Clear the current alert status.
  - checkAlert
```
void checkAlert()
         throws AlertException
```
    Check if an alert has been raised and throw an AlertException if it has.
    
    Throws:
    
    AlertException - if alert has been raised.